Adjustable and Suppressible Gas Operating System for an Automatic Firearm

ABSTRACT

A gas operating system for a firearm comprises a gas block defining a cylinder, a discharge gas vent coupled to the cylinder near a proximal end of the cylinder and a discharge gas inlet configured for pneumatic coupling with the barrel of a firearm near the proximal end of the cylinder. A piston in the cylinder is movable from a rest position distal of the discharge gas vent and the discharge gas inlet against the action of a return spring by discharge gas from a barrel of a firearm pneumatically coupled to the discharge gas inlet. A regulator is pneumatically coupled to the discharge gas vent to selectively control the flow of discharge gas from the discharge gas vent to modulate a volume of discharge gas advancing the piston. A diffuser may be provided pneumatically coupled to the regulator for diffusing any audible or visual report.

RELATED APPLICATIONS

This application claims priority from U.S. Provisional Patent Application Ser. No. 61/141,583, filed Dec. 30, 2008, entitled “Adjustable and Suppressible Gas Operating System for an Automatic Firearm” which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention is directed to firearms, and more particularly to an adjustable and suppressible gas operating system for an automatic firearm.

BACKGROUND

Gas operating systems are well known in the firearm arts and have been used for many years to automatically reload firearms. Gas operating systems use a portion of the gases generated from firing of the firearm (hereinafter, discharge gas) to drive an internal reload mechanism.

Sometimes more or less power may be necessary to drive the gas operating system depending on various factors such as build up of particulates in the gas discharge system and how the firearm is being used. For example, as particulate deposits collect within the gas discharge system, more power may be required to drive the system. In another example, if the firearm uses a sound suppressor on the muzzle of the barrel this may act to increase the pressure and duration of the discharge gas supplied to the gas operating system. In this instance it may be desirable to limit the supply of discharge gas to the gas operating system to prevent overpowering the system which may damage or fatigue components of the operating system. Thus, a reliable mechanism for controlling the amount of discharge gas available for driving the gas operating system is desired.

Venting of discharge gas from the gas operating system is one way to limit discharge gas driving the gas operating system. However venting discharge gas may lead to a visual or audible report which may be undesirable. The problem of a visual and audible report is enhanced when more discharge gas is vented from the system. This may be particularly acute in the example discussed above where a suppresser is utilized on the muzzle of the barrel of an automatic firearm. While there is a need to vent a greater amount of discharge gas from the gas operating system with the use of a suppresser on the barrel of a firearm, the visual and audible report resulting from venting of the discharge gas can act to undermine the very benefits sought by the use of the suppresser. Thus, a lightweight, inexpensive and reliable manner to diffuse the visual and audible report from discharge gases vented by the gas operating system is desired.

The present invention is directed toward overcoming one or more of the problems discussed above.

SUMMARY OF THE EMBODIMENTS

A first aspect of the invention is a gas operating system for a firearm. The gas operating system comprises a gas block defining a cylinder, a discharge gas vent pneumatically coupled to the cylinder near a proximal end of the cylinder and a discharge gas inlet configured for pneumatic coupling with the barrel of a firearm near the proximal end of the cylinder. A piston resides in the cylinder. The piston is movable from a rest position distal of the discharge gas vent and the discharge gas inlet against the action of a return spring by discharge gas from a barrel of a firearm introduced into the inlet upon discharge of a firearm having a barrel pneumatically coupled to the discharge gas inlet. A regulator is pneumatically coupled to the discharge gas vent to selectively control the flow of discharge gas from the discharge gas vent to modulate a volume of discharge gas advancing the piston. In one embodiment the regulator comprises orifices of different sizes which can be selectively pneumatically coupled to the discharge gas vent to selectively control the flow of discharge gas from the discharge gas vent. This embodiment may comprise the regulator being attached to the gas block and rotatable relative to the gas block about a rotation axis. The at least two orifices are radially spaced from the axis and are configured to be selectively pneumatically coupled to the gas discharge vent by rotation of the regulator about the rotation axis. Another embodiment may further include the gas block defining a cylindrical cavity communicating with the discharge gas vent. In this embodiment the regulator comprises a cylindrical plug sized to be received in the cylindrical cavity along the rotation axis. The at least two orifices are defined in the cylindrical plug. To facilitate disassembly and cleaning of the gas operating system including the regulator, the regulator may be removably attached to the gas block. The regulator may be removably attached to the gas block by a pair of lugs extending radially from the cylindrical plug which may be selectively received in an annular channel in the cylindrical cavity configured to receive the lugs. The regulator may further comprise a plurality of notches about the cylindrical plug and the gas block may further comprise a spring loaded detent. The notches, the spring loaded detent and the orifices are configured for the spring loaded detent to extend into a notch with a select one of the at least two orifices pneumatically coupled to the gas discharge vent. Means may further be provided for removably attaching the diffuser to the regulator.

Another aspect of the invention is an automatic firearm comprising a gas operating system as described above. A diffuser comprising an expansion chamber is provided with the expansion chamber pneumatically coupled to the discharge gas vent.

The gas operating system using a regulator pneumatically coupled to the discharge gas vent to selectively control a flow of discharge gas from the discharge gas vent allows for the regulation of discharge gas provided to the gas operating system while removing the regulator from the immediate vicinity of the firearm barrel. As a result, the regulator is subjected to reduced pressure from the discharge gas because a portion of the discharge gas from the firearm is always used to operate the gas operating system. In addition, the regulator will be subject to substantially less wear as well as less buildup of particulate debris on the regulator which, with time, degrades the utility of the regulator. Because the regulator allows for a select amount of discharge gas to be used to drive the gas operating system, only enough gas necessary to reliably power the gas operating system without overdriving it can be provided to the gas operating system. For example, in one embodiment three gas settings may be available: regular, extra power and suppressed. The “regular” setting is used for normal operation and features an orifice designed to vent only enough gas to reliably power the gas operating system without overdriving it. “Extra power” uses a constricted orifice to allow more gas to operate the piston if the weapon is fouled through extended use without cleaning or because of environmental debris. The “suppressed” setting is used in conjunction with a sound suppressor on the muzzle of a barrel of a firearm and has the largest sized orifice to vent a greater volume of gas to prevent overdriving of the gas operating system. The diffuser in accordance with the present invention is particularly advantageous when a suppressor is used on a firearm utilizing the gas operating system. The diffuser functions to minimize both the audible and visual report of vented discharge gas of the gas operating system which might otherwise defeat the advantages of the suppressor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a barrel of a firearm including a gas operating system in accordance with the invention;

FIG. 2 is an exploded view of a regulator and diffuser for use with the gas operating system of FIG. 1;

FIG. 3 is a top plan view of FIG. 1; and

FIG. 4 is a partial cross-section of the gas operating system taken along line 4-4 of FIG. 3.

DETAILED DESCRIPTION

Unless otherwise indicated, all numbers expressing quantities of ingredients, dimensions reaction conditions and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”.

In this application and the claims, the use of the singular includes the plural unless specifically stated otherwise. In addition, use of “or” means “and/or” unless stated otherwise. Moreover, the use of the term “including”, as well as other forms, such as “includes” and “included”, is not limiting. Also, terms such as “element” or “component” encompass both elements and components comprising one unit and elements and components that comprise more than one unit unless specifically stated otherwise.

FIG. 1 illustrates a barrel 10 of a firearm having a gas operating system 12 operatively associated therewith. The gas operating system 12 comprises a gas block 14 physically attached to the barrel and pneumatically coupled to the barrel, a drive rod 16 extending from the gas block 14 and a return spring 18 which biases the drive rod 16 and an associated piston residing in the gas block to a rest position. As is known in the art, on discharge from a firearm utilizing the barrel 10, discharge gas from the barrel drives the piston within the gas block rearward relative to the muzzle 20 enabling the drive rod 16 to drive an automatic reload mechanism of the firearm. The gas operating system 12 includes a regulator 22 for venting discharge gas from the gas operating system to selectively control the power provided to the drive rod 16 to operate the reloading mechanism. A diffuser 24 is connected to the regulator 22 to suppress a visual and audible report that may result from venting of discharge gas from the regulator 22.

FIG. 2 is an exploded view of the regulator and diffuser. The regulator 22 has a generally cylindrical body extending along rotation axis 27 including a reduced diameter plug 26 having a pair of radially extending lugs 28 near a distal end 29 of the plug. Between the lugs 28 and the distal end 29 of the plug 26 is an annular groove 30. Opposite the plug 26 the regulator body defines a cylindrical cavity 32. Internal threads 33 reside near an opening of the cylindrical cavity 32. A seal ring 34 is configured to be received in the annular groove 30 as will be described in greater detail below. In the particular embodiment described herein, three equally spaced notches 36 are defined at a stepped portion of the regulator body near a proximal end of the plug 26. These notches 36 cooperate with the detent 38 biased by the coil spring 40 with the regulator assembled in the gas block as will be described in greater detail below for selective rotational positioning of the regulator within a cylindrical cavity 42 defined in the gas block 14. The number of notches is equal to the number of axial orifices in the plug, as will be described in greater detail below.

The diffuser 24 depicted in FIG. 2 consists of a cylindrical body 46 having two radial baffles 48 extending axially along the rotation axis 27. The cylindrical body 46 has external threads 50 configured for threaded engagement with the internal threads 33 of the cylindrical cavity 32. As depicted in FIG. 4, the cylindrical body 46 defines an interior cavity 51. A pair of opposing notches 52 is defined in a lip 53 of the cylindrical body 46 defining the interior cavity 51. An annular groove 54 resides between the external threads 50 and the lip 53 of the cylindrical body 46. Lock ring 56 is configured to be received in the annular groove 54 and includes an axial pin 58. With the diffuser 24 threadably engaged with the regulator 22 as depicted in FIG. 4, the lock ring 56 and axial pin 58 prevent relative rotation between the diffuser 24 and the regulator 22.

FIG. 3 is a top plan view of the barrel and gas operating system of FIG. 1. FIG. 4 is an assembled cross-sectional view taken along line 4-4 of FIG. 3 illustrating the gas operating system, regulator and diffuser in an assembled state. Referring to FIG. 4, the gas block 14 is seen to define a cylinder 64 having an inlet 66 near a proximal end 68. As depicted in FIG. 4, the inlet 66 is configured for pneumatic coupling to a hole 68 in the barrel 10 communicating with the barrel bore 70. A piston 72 is illustrated in the cylinder 64 in a rest position. The piston 72 receives the drive rod 16. The gas block 14 further defines a discharge gas vent 74 radially displaced from the rotation axis 27. The discharge vent 74 communicates with the cylindrical cavity 42 of the gas block 14.

As depicted in FIG. 4, the plug 26 is received in the cylindrical cavity 42 along the rotation axis 27. The radial lugs 28 are received in an annular channel 76 defined in the cylindrical cavity 42. Three axial orifices 80, 82, 84 are provided in the plug 26, the axial orifice 80 having the smallest cross-section, the axial orifice 82 having a medium cross-section, and the axial orifice 84 having the greatest cross-section. The axial orifices 80, 82, 84 are radially spaced the same distance from the rotation axis 27 in 120° offsets. Other embodiments could include any number of axial orifices greater than 1 (e.g., 2, 4, 5, etc.) which are preferably radially equally spaced. The detent 38 biased by the cylindrical coil 40 is received in a bore 86 in the gas block 14. An end of the detent 38 is selectively engageable with the notches 36 by rotation of the regulator 22 about the rotation axis to bring a desired one of the axial orifices 80, 82, 84 into pneumatic communication with the discharge gas vent 74. In this manner, the amount of gas vented from the cylinder 64 and thus the amount of gas available to drive the piston 72 can be selectively varied. The seal ring 34 received in the annular groove 30 forms a seal around the periphery of the plug to minimize the escape of the discharge gas between the plug 26 and the cylindrical cavity 42.

The diffuser 24 is shown threadably engaged in the cylindrical cavity 32 of the regulator 22. Each of the axial orifices 80, 82, 84 is in pneumatic communication with the cylindrical cavity 32. With the diffuser 24 installed as depicted in FIG. 4, the diffuser 24 and the cylindrical cavity 32 cooperate to define an expansion chamber. The baffles 48 reside between the expansion chamber 87 and the diffuser outlets 88 to provide communication between the expansion chamber 87 and the diffuser exit 90.

In operation, the regulator 22 is rotatable about the rotation axis 27 to bring a select axialorifice 80, 82, 84 into pneumatic communication with the discharge gas vent 74. The detent 38, the notches 36 and the axial orifices 80, 82, 84 are configured so that with the detent 38 received in a notch 36, a select orifice is aligned with the discharge gas vent 74. Thus, by simple rotation of the regulator 22 about the rotation axis 27 the desired amount of discharge gas can be made available to drive the piston 72 of the gas operating system. With the diffuser 24 deployed as depicted in FIG. 4, gas from the aligned axial orifice enters the cylindrical cavity 32 which cooperates with the diffuser 24 to define an expansion chamber 87. The baffles 48 contribute to turbulence within the expansion chamber 87 which diminishes the audible and visual report of the vented discharge gas as it leaves the diffuser exit 90.

The regulator 22 can be readily disassembled from the gas block 14 by depressing the detent 38 thereby allowing it to ride outside of its normally constrained track and bypassing the gas setting notches 36. This allows the regulator additional rotational freedom to align the lugs 28 with the axial slots 93 in the gas block. These slots interrupt the gas block annular channel 76 allowing the regulator to be removed. In this manner, the venting side of the gas block and the diffuser can be cleaned as desired. Similarly, by removing the block ring 56 the diffuser 24 can be unscrewed from the regulator 22 for cleaning of the diffuser and the regulator.

Various embodiments of the disclosure could also include permutations of the various elements recited in the claims as if each dependent claim was multiple dependent claim incorporating the limitations of each of the preceding dependent claims as well as the independent claims. Such permutations are expressly within the scope of this disclosure.

While the invention has been particularly shown and described with reference to a number of embodiments, it would be understood by those skilled in the art that changes in the form and details may be made to the various embodiments disclosed herein without departing from the spirit and scope of the invention and that the various embodiments disclosed herein are not intended to act as limitations on the scope of the claims. All references cited herein are incorporated in their entirety by reference. 

1. A gas operating system for a firearm comprising: a gas block defining a cylinder, a discharge gas vent pneumatically coupled to the cylinder near a proximal end of the cylinder and a discharge gas inlet configured for pneumatic coupling with a barrel of a firearm near the proximal end of the cylinder; a piston residing in the cylinder, the piston being movable from a rest position distal of the discharge gas vent and the discharge gas inlet against the action of a return spring by discharge gas from a barrel of a firearm introduced into the inlet upon discharge of a firearm having a barrel pneumatically coupled to the discharge gas inlet; and a regulator pneumatically coupled to the discharge gas vent to selectively control a flow of discharge gas from the discharge gas vent to modulate a volume of discharge gas advancing the piston.
 2. The gas operating system of claim 1 wherein the regulator comprises at least two orifices of different size which can be selectively pneumatically coupled to the discharge gas vent to control the flow of discharge gas from the discharge gas vent.
 3. The gas operating system of claim 2 further comprising the regulator being attached to the gas block and rotatable relative to the gas block about a rotation axis, the at least two orifices being radially spaced from the axis, and the orifices being configured to be selectively pneumatically coupled to the gas discharge vent by rotation of the regulator about the axis.
 4. The gas operating system of claim 3 further comprising the gas block defining a cylindrical cavity communicating with the discharge gas vent and the regulator comprising a cylindrical plug sized to be received in the cylindrical cavity along the rotation axis, the at least two orifices being defined in the cylindrical plug.
 5. The gas operating system of claim 4 further comprising means removably attaching the regulator to the gas block.
 6. The gas operating system of claim 5 wherein the removably attaching means comprises a pair of lugs extending radially from the cylindrical plug and annular channel in the cylindrical cavity configured to receive the lugs.
 7. The gas operating system of claim 6 wherein the regulator further comprises a plurality of notches about the cylindrical plug and the gas block further comprises a spring loaded detent, the notches, the spring loaded detent and the orifices being configured for the spring loaded detent to extend into a notch with a select one of the at least two orifices pneumatically coupled to the gas discharge vent.
 8. The gas operating system of claim 1 further comprising a diffuser pneumatically coupled to the discharge gas vent.
 9. A gas operating system for a firearm comprising: a gas block defining a cylinder, a discharge gas vent pneumatically coupled to the cylinder near a proximal end of the cylinder and a discharge gas inlet configured for pneumatic coupling with a barrel of a firearm near the proximal end of the cylinder; a piston residing in the cylinder, the piston being movable from a rest position distal of the discharge gas vent and the discharge gas inlet against the action of a return spring by discharge gas from a barrel of a firearm introduced into the inlet upon discharge of a firearm having a barrel pneumatically coupled to the discharge gas inlet; and a diffuser comprising an expansion chamber, the expansion chamber being pneumatically coupled to the discharge gas vent.
 10. The gas operating system of claim 9 further comprising a regulator pneumatically coupled between the discharge gas vent and the diffuser to selectively control a flow of discharge gas from the discharge gas vent to modulate a volume of discharge gases advancing the piston.
 11. The gas operating system of claim 10 wherein the regulator comprises at least two orifices of different size which can be selectively pneumatically coupled to the discharge gas vent to selectively control the flow of discharge gas from the discharge gas vent.
 12. The gas operating system of claim 11 further comprising the regulator being attached to the gas block and rotatable relative to the gas block about a rotation axis, the at least two orifices being radially spaced from the rotation axis, and the orifices being configured to be selectively pneumatically coupled to the gas discharge vent by rotation of the regulator about the rotation axis.
 13. The gas operating system of claim 12 further comprising the gas block defining a cylindrical cavity communicating with the discharge gas vent and the regulator comprising a cylindrical plug sized to be received in the cylindrical cavity along the rotation axis, the at least two orifices being defined in the cylindrical plug.
 14. The gas operating system of claim 13 further comprising means removably attaching the regulator to the gas block.
 15. The gas operating system of claim 14 wherein the removably attaching means comprises a pair of lugs extending radially from the cylindrical plug and annular channel in the cylindrical cavity configured to receive the lugs.
 16. The gas operating system of claim 15 wherein the regulator further comprises a plurality of notches about the cylindrical plug and the gas block further comprises a spring loaded detent, the notches, the spring loaded detent and the orifices being configured for the spring loaded detent to extend into a notch with a select one of the at least two orifices pneumatically coupled to the gas discharge vent.
 17. The gas operating system of claim 11 further comprising means removably attaching the suppressor to the regulator with the orifices pneumatically coupled to the expansion chamber.
 18. The gas operating system of claim 9 further comprising a suppressor operatively associated with a muzzle of the barrel.
 19. The gas operating system of claim 17 further comprising a cylindrical cavity defined in the regulator opposite the cylindrical plug, the diffuser comprising at least one radical baffle inserted in the cylindrical cavity of the regulator, the cylindrical cavity and the baffle cooperating to define the expansion chamber, and the means removably attaching the diffuser to the regulator comprises mating threads between the cylindrical cavity and the regulator.
 20. An automatic firearm comprising: a gas operating system comprising a gas block defining a cylinder and a piston within the cylinder, the cylinder being pneumatically coupled to a barrel of the automatic firearm, the piston being advanced in the cylinder against the action of the return spring by discharge gas released in the barrel upon firing the automatic firearm and the gas block further comprising a discharge gas vent pneumatically coupled to the cylinder; a regulator pneumatically coupled to the discharge gas vent to selectively control a flow of discharge gas from the discharge gas vent to modulate a volume of discharge gas advancing the piston; and a diffuser comprising an expansion chamber, the expansion chamber being pneumatically coupled to the regulator. 